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more clearly than would actual photomicrographs of the fibers themselves; the only criticism that can be offered is that such drawings are apt to be more or less idealized, or rat1,er conventionalized, with the result that unless a person is t180roughiy familiar with just what features are to be o microscope, he would experience difficult)- in n:any cases in identiij-ing some of the fibers drawn bp ITdinel. Another criticism to be offered is that though Hohnel’s bc,r.Tc is en:inently scientific and must always cccupy a high place in 11 e liter-t a ure of the subject, the technical or practical side of tl c n-:attrr is rather badly neglected, which is rather disappcinting in a book purporting to deal with tl;e “technically applied fibcrs. To the scientist or advanced student interested in tke subject the present volume is wEat may be terned a valued “classic,” but to the purely technical student and the one to whom tEe volume should make the greatest appeal and he of the greatest utility, Holinel’s book, we fear 611 be too highly theoretical for practical use. J. MERRITT MATTHEWS. ”
A SYSTEMATIC COURSE O F P R A C T I C A L O R G A N I C CHEMISTRY. By LIOXEI, GUYRADCLIFFEand FRANK S T U R D YS I N N A T T . London : Longrriaiis, Green 8 Co. 1905. x i T 2 6 4 pp P-ice, $1.40
The systematic course (96 pages) begins with XetEcds for the detection of the various elements present in organic ccmpounds ; the determination of melting-point, boiling-pcint, and specific gravity ; the purification of organic substances (crystallization and sublimation) ; and the determination of rcolecular and equivalent weights. This introductory portim ( 2 2 pages) is followed b y detailed descriptions of the preparation of various typical organic compounds, accompanied by numerous experiments illustrating their characteristic reactions. Tbese preparations and experiments are so arranged as to follow along with the lectures on the theoretical side of the subject, and can all be completed b y a student “working five hours per week” (presumably during one academic year). Following the systematic course, comes a special part for advanced students (140pages), jo pages of which are devoted t o ‘‘Qualitative Organic Analysis Required for the Board of Education Examination, Stage 11.” This portion is inserted for the benefit of students preparing for these particular examinations,
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and the authors themselves are not very enthusiastic about it, for they explain that they “are quite sensible of the fact that the analysis of such mixtures cannot be regarded as useful practical organic chemistry.” Then come a number of additional preparations, methods for determining vapor density, the ebullioscopic and cryoscopic methods of establishing molecular weights, ultimate analyses, alkaloidal reagents, and so forth. All illustrations are purposely omitted. The students design their own apparatus, or a model of the apparatus is set up by the instructor. It is no doubt a good plan to encourage beginners to design their own apparatus, but there seems to be no good reason (aside possibly from the slight additional expense) why the apparatus which the assistant is supposed to set up as a model should not be figured. Reaction equations are likewise left out, the student being expected to look them up for himself. Too many of the tests appended to the various preparations apply only to the individual compound, and are not in any sense group reactions. In those cases where the chemistry of the change is but imperfectly understood, as with many of the color and pyrogenetic reactions, the educational value of the test is but slight. Such tests are all well enough for analytical purposes, but are rarely of much assistance in understanding the theoretical side of the subject. The fundamental theoretical considerations upon which the preparations and reactions are based should be brought out much more clearly, including fuller explanations of the origin of the various by-products and the way in which they are removed. Greater stress should be laid upon the purification of the crude products. Failure to emphasize this point is apt to encourage careless and slovenly work. Errors of various kinds are numerous. Incorrect statements are few, mistakes due to careless proof-reading are frequent. In the former category would fall the statement (on page 142)that the action of bromine water upon salicylic acid gives a precipitate of tribromsalicylic acid, whereas the product is really tribromphenol bromide. Among the errors due to careless proof-reading are many which are confusing and misleading. There is space here to mention but few of these. On page 3 2 , a solution containing ethyl alcohol is oxidized and the oxidation product tested for formic acid. On page 182, in the preparation of ethyl nitrate, a
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misplaced comma is responsible for the statement that ’ ‘when nitric acid alone is used, the acid oxidizes, some of the alcohol being itself reduced to nitrous acid ’ ’ On page 184, ecolution appears instead of solution On page 194, in describing the preparation of quinoline, the student is told that, .tfter the first stage o f the reaction has been inductd bq gentle wa-ining, tlie flaiiie must then be i e n e x d Sucli a misprint m i \ lead to serious results, as this reaction is uric which often proceeds TI it11 evplosire riolence even nhen t le flmLeis i e i i z c w d C,n pcge 196, in describing the synthesis oi‘ succinic acid, ‘1 11 andering semicolon Causes it to appear that et:i> h e dibroiriide is boiled with potassium c>anide, and cth? leiie dicyaiiide is luiLnedciii hj-drolysis ’ On page z r S line 5 i r m i the top, t h e aiiission of ‘ ilot” ccmpletel! rererscs nliat t h e authors inteiided tc>s ~ y In other caseq, the language is anyt5ing but clt=ar Take, for example, the following test for albumin (page 204) : “Stioiig nitric acid yields a nhite precipitate, nhich 011 l,oi!iiig becoilicy yellow, and after cooliiig tlie addition of ainmonin becomes darker (orange) ” llie selection u i preparations is 5150 open to criticisiii The preparatim and handling of hydrogen cyanide, for example, is too danger(ms for any but experienced hands -1disproportionate amount of space is ‘ilbtted to tlie alkniuids. The book is evident!? prepared tiI‘ii;il>y for the chemical students in the !.Ianchester Municipal Scliocl o f Technology, to be used onlv under tlie supervision of t’ic demonstrator, to whoin the student is constantly referred for furt?ier information and advice, and u-ithout vhose assistance the book would be of but little service It is printed on one side ol the paper only, so that the actual number of pages of text is but half that given. The blank side of the page is for the student to record reactions, observations, and so forth ; but, as he is supposed to keep a note-book also, the need of the blank pages is not obvious. The size of the volume is further increased by the inclusion of a @-page list of books for sale by the publishers. The book contains many good features and, with the changes above suggested, should prove useful. MARSTON TAYLOR BOGERT. ”
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